Treating head lice
What are head lice?
Head lice are tiny insect parasites that live on your head and feed on your scalp (the skin covering your head).
Find out more about head lice.
How do I treat head lice?
There are two effective head lice treatments. Be sure to follow the directions for your preferred treatment exactly.
The 10-day hair conditioner treatment
Head lice can be removed by applying plenty of hair conditioner to dry hair and then combing to remove live lice and eggs. The conditioner makes it hard for the lice to move and traps them in the teeth of the comb. The conditioner also detangles hair, making combing easier.
Why does the treatment take 10 days?
Eggs generally hatch 7 to 10 days after being laid on the hair shaft (the part of your hair closest to the scalp). The 10-day treatment period helps break the reproductive cycle of the head lice. Even if only one or two adult lice are missed, they can lay about 6 eggs per day, and the cycle of outbreaks will continue.
Combing out new hatchlings every 1 to 2 days also means they cannot lay further eggs, which can happen about a week after hatching.
What do I need?
- Any type of hair conditioner, including generic ‘home’ brands. Using white hair conditioner may make it easier to see the head lice.
- A metal fine-tooth ‘nit comb’ (available from most pharmacies).
What to do
- Apply plenty of hair conditioner to the dry hair until it is saturated.
- Comb through with an ordinary comb or brush to remove tangles.
- Section and comb the hair thoroughly with the nit comb in 4 directions – forwards, backwards, left and right.
- Wipe the comb on a white paper towel to check that the dark adult lice or the paler hatchlings (young lice) are being removed. You may need to use a magnifying glass and a strong light to see the lice and eggs.
- Continue combing the hair in sections until the whole head has been checked.
- Some eggs will be removed by combing but you may need to use your fingernails to remove as many eggs as possible from the base of the hair shaft near the scalp. Hatchlings that emerge from missed eggs will be removed by combing with conditioner over the 10-day period. Only eggs within 1cm of the scalp will hatch. Eggs that have grown further out with the hair shaft will have already hatched or died.
- When you have finished checking, rinse the conditioner out and dry the hair.
- Repeat this process every 1 to 2 days over the 10-day treatment period. To save time during a school week, consider this combing schedule: Tuesday, Thursday, Saturday, Sunday, Tuesday, Thursday.
- Check the waste material you comb out for adult head lice each day after combing. If any are found, this indicates a new outbreak and you will need to start again from day 1, as new eggs may have been laid by the adult lice.
- Check for head lice once a week for at least 4 weeks after you complete the 10-day treatment. You may wish to do this on the weekend when you have more time. Applying plenty of hair conditioner makes combing easier and more effective.
- Check all other household members for head lice and treat as necessary.
Three groups of insecticide (chemicals used to kill or control insects) have been shown to be effective and safe treatments for head lice. These are permethrin, pyrethrin and malathion.
Some other treatments may not have been properly tested and may be ineffective, expensive or even unsafe. Check the product labels for active ingredients.
To avoid adverse reactions the following people should not routinely use insecticide head lice treatments:
- babies under 6 months
- people with asthma, epilepsy, insecticide allergies, scalp conditions or very sensitive skin
- women who are pregnant or breast-feeding.
People who cannot use insecticides should use the 10-day hair conditioner treatment instead.
Key points about insecticides
- No insecticide is guaranteed to kill all eggs. Eggs which are not killed or removed manually will hatch 7 to 10 days after being laid.
- Following insecticide treatment, remove as many remaining eggs as possible with your fingernails. Use a magnifying glass in strong light, and concentrate on ‘live’ eggs, which are found within 1 cm of the scalp.
- If insecticide alone is used, it should be applied on days 1, 7 and 14 to kill any hatchlings before they lay more eggs. However, if after the first insecticide treatment the 10-day conditioner method is used, there is no need for the second and third insecticide treatments.
- To prevent skin irritation, do not repeat insecticide treatment more than 3 times, 1 week apart.
- Some head lice may be resistant to an insecticide and will still be alive the morning after the treatment. If this happens, thoroughly wash out the first insecticide and re-treat the hair the same day with another type of insecticide (for example, permethrin, pyrethrin or malathion), not a different brand of the same type of insecticide. Alternatively, change to the 10-day hair conditioner treatment instead.
Using an insecticide treatment
- Before using the insecticide, rinse out any hair conditioner as it may stop the insecticide from working. Follow the product information and instructions.
- Lift the hair in sections and saturate the hair with the insecticide.
- Comb the insecticide through with an ordinary comb from the scalp to the ends of the hair. Work from the back of the head to the front. Pay particular attention to treating behind the ears, at the back of the neck and close to the scalp.
- Leave the insecticide on for the time recommended in the product information, then wash out.
- Section the hair again and comb through with a metal fine tooth nit comb to remove dead lice and eggs.
- Check that the head lice are actually dead. Do this straight after the recommended treatment time and again the next morning. It may take a few hours for all the lice to die. Remember, if any head lice are found still alive the next morning, re-treat the hair the same day with another type of insecticide (for example, permethrin, pyrethrin or malathion), not a different brand of the same type of insecticide. Alternatively, change to the 10-day hair conditioner treatment.
Check all other household members and close contacts for head lice and treat as necessary.
Head lice and eggs do not survive long away from your scalp as they are human parasites. It is not necessary to:
- wash all your household linen or clothing
- scrub or spray your house with insecticide
- treat your dog or cat.
As pillow slips and towels may be soiled with head lice waste they should be washed on the first day of treatment.
Stay home from school
Under the School Education Act 1999, if your child has head lice a principal may keep him or her away from school until treatment has started.
Your child may return to school when all live head lice have been removed. There is no need to stay away from school if there are only a few remaining eggs, but you must continue treatment over the following 10 days to ensure that all eggs and hatchlings have been removed.
A repellent is a substance that discourages insects from settling. There are no tested and proven repellents for head lice.
Head bands and caps coated with insecticide may kill any head lice they come in contact with. They need to be worn all the time, however, and do not kill all head lice eggs. Insecticides may also cause skin irritation.
What if the treatment hasn’t worked?
If treatment is unsuccessful, check you have done the following:
- Did the chosen treatment cover the 10-day hatching cycle of the eggs?
- Did you check the waste from the comb for adult head lice (indicating new outbreaks) over the 10-day period?
- Were as many eggs as possible removed every day?
- Was hair conditioner applied to dry hair, not wet?
- Was enough hair conditioner applied to saturate the hair?
- If an insecticide was used, was it applied exactly as instructed and for the recommended application time?
- Was a metal fine-tooth nit comb used?
If your child has head lice you can contact your Community (School) Nurse for further assistance.
Environmental Health Directorate, Public Health
This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.